If the radius of a star is $R$ and it acts as a black body,what would be the temperature of the star,in which the rate of energy production is $Q$? ($\sigma$ stands for Stefan's constant)

• A
  $\frac{Q}{4\pi \sigma R^2}$
• B
  $\left( \frac{Q}{4\pi \sigma R^2} \right)^{1/2}$
• C
  $\left( \frac{Q}{4\pi \sigma R^2} \right)^{1/4}$
• D
  $\left( \frac{4\pi \sigma R^2}{Q} \right)^{1/4}$